Does gender have an effect in the prevalence of types of glaucoma in Pakistani population? Objective: Study Design: Patients and Methods: Results:

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1 Does gender have an effect in the prevalence of types of glaucoma in Pakistani population? Farah Akhtar 1,, Shazia Micheal 2, Muhammad Imran Khan 2, Sajeela Yousaf 2, Muhammad Bilal 3, Asifa Ahmed 2, Raheel Qamar 2, 4 Objective: To assess the prevalence of various types of glaucoma, blindness and severity of disease with respect to gender differences. Study Design: A hospital based retrospective study. Patients and Methods: Study included 3021 patients presenting to glaucoma clinic. Type and severity of glaucoma in the patients was analyzed to determine the gender inequality. Data was analyzed with the statistical software SPSS. Results: It was found that overall ratio of males affected with glaucoma was higher than females (2.3: 1). POAG was more prevalent in males whereas females were suffering more from PCAG. Although the overall prevalence of glaucoma was higher in males but the blindness rate in all types of glaucoma was more in females. Due to severity in POAG surgery of more number of females was performed. PEXG and NTG were more pronounced in males. Conclusion: s have more prevalent PCAG while males were more affected from POAG. Overall the blindness rate in different types of glaucoma was higher in females. Therefore the results of present study indicate that gender does have an effect in the prevalence and blindness resulting from different types of glaucoma. Al-Shifa Journal of Ophthalmology 2010; 6(1): Al-Shifa Trust Eye Hospital, Rawalpindi, Pakistan. Glaucoma is a neurodegenerative disease of the optic nerve which occurs due to the progressive loss of optic nerve axons and death of the retinal ganglion cells (RGCs) 1. It is the second leading cause of blindness affecting 70 million people worldwide and it has been estimated that the prevalence 1. Al-Shifa Trust Eye Hospital Rawalpindi, Pakistan, 2. Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan, 3. POF Hospital, Wah Cantt, Pakistan, 4. Shifa College of Medicine, Islamabad, Pakistan. Originally received: Apr 13, Revised: May 27,2010. Accepted: June 23, Correspondence to: Farah Akhtar, FCPS, DOMS, MBBS, Al- Shifa Trust Eye Hospital, Jhelum Road, Rawalpindi -400, Pakistan. Phone: akhtar_705@yahoo.com. of glaucoma will be increased and the turnover of the number of cases will be 79.6 million in the year As glaucoma is a heterogeneous and multifactorial disease therefore it represents a number of different conditions which are responsible for the damage of the optic nerve and loss of vision associated with visual field defects and elevated intraocular pressure 3. In recent years the gender difference has attained much attention in the prevalence of various types of glaucoma in populations of different countries and continents. There is a requirement of fastidious consideration to gender differences in blindness for understanding the targets for blindness reduction and in the development of interventions. In different neurodegerative and blinding eye diseases it has been observed that gender have quite important targets and role in the manifestation, progression and commencement of the disease. s have 1.9 times higher risk of developing dementia and Alzheimer s disease by 3.1 1

2 Akhtar et al. Effect of gender on prevalence of types of glaucoma times. Most of the American studies reported equal rates whereas Europeans had shown higher rates of dementia in women. Also females have increased risk of developing hypertension, hyperlipidemia, and diabetes as compared to men. It has been observed that although gender differences in neurodegenerative processes are still unexplored, they appears to offer great promise for the future development of better strategies for the cure of diseases and betterment of patients 4-7. In recent years it is a topic of concern in the eye diseases that does gender have any effect or not and there are different reports explaining importance of gender. Rudnicka AR et al had concluded through a meta-analysis study of 46 studies that males have increased risk of developing primary open angle glaucoma relative to females 8. Similarly the impact of axial myopia, age, and retinal detachment history as risk factors for pseudophakic retinal detachment were seen predominantly in males 9. Occurrence of myopia and hyperopic refractive errors, changes in pattern of astigmatism and corneal structure with age are also influenced by gender 10, 11. The aim of the present study was therefore to determine the prevalence of various types of glaucoma and blindness resulting from them with respect to gender. Materials and Methods The present retrospective study is based on the analysis of data collected after reviewing the records of the 3021 patients who had visited the glaucoma clinic of Al- Shifa Trust Eye Hospital Rawalpindi from August 2006-August All the data was confirmed again by the Ophthalmologist who had done the detailed examination of all the patients. Criteria for the data were based on the standard conditions of diagnosis for each type of glaucoma. The types of glaucoma which were studied included primary open angle (POAG), primary closed angle (PCAG), pseudoexfoliative (PEXG), normal tension (NTG), neovascular (NVG), steroid induced (SIG), glaucoma suspects, and the remaining types were included in the data of other types of glaucoma. The ophthalmic examination of the patients included testing for best corrected visual acuity with the help of Snellen s chart, Goldman applanation tonometery to measure intraocular pressure (IOP), slit lamp biomicroscopy, indirect ophthalmoscopy to determine cup-to-disc ratio (c/d), visual field defects determined with Humphrey 30 2, and gonioscopy to assess type of glaucoma. Criteria of POAG include IOP of more than 21 mmhg, typical glaucomatous cupping of the optic disc (diffuse or focal thinning of the disc rims and cup-to-disc ratio of more than 0.5), visual field defects typical of glaucoma and an open anterior chamber angle. PCAG was defined by the same criteria as POAG except that in PCAG, a gonioscopically closed anterior chamber angle was noted. In case of PEXG, patients were evaluated by slit lamp biomicroscopy for the presence of exfoliative material along the papillary border and on the iris without dilating the eye. After pupil dilation the patients were also analyzed for the presence of white material deposits on the anterior lens surface. NTG patients were classified as having IOP in normal range but progressive optic nerve changes with open angle and visual field defects. NVG catagoried by the neovascularization on the iris, increased IOP and severe pain, and SIG by raised IOP due to the administration of steroids and glucocorticoids. The other types of glauocma included glaucoma associated with different syndromes, secondary glaucomas and developmental, congenital, aphakic, pseudophakic, post traumatic, post vitrectomy, corneo-iridic scar, uveitic glaucoma etc. The data was analyzed to determine the overall prevalence of various types of glaucoma, with respect to 2

3 Al-Shifa Journal of Ophthalmology, Vol. 6, No.1, Jan/June, 2010 gender as well blindness caused by these types and the number of surgeries required in males and females by using statistical software SPSS version 16. Results Out of total 3021 patients of glaucoma, male to female ratio was 2.3:1 which indicates that in our region males are more affected than females from glaucoma. In table 1 the overall prevalence of different types of glaucoma has been shown and it was observed that POAG comprised the.3% of the total glaucoma patients. PCAG is the second and PEXG is the third prevalent type but as shown in the table, more individuals were blind due to PCAG and NVG as compared to POAG, which is more prevalent. With regards to family history of glaucoma it was observed that first degree relatives of PCAG patients have a greater chance of developing glaucoma compared to other types. Table 1 shows that 15.4 % of the PCAG patients had their relatives positive for glaucoma. More cases of advanced disease were observed in POAG and 32% of the patients were operated to achieve better control of the disease. In table 2 correlation of various types of glaucoma with gender has been shown and it was observed that males had more chances of developing POAG, PEXG, NVG, SIG and traumatic glaucoma as compared to females, who were more prone to PCAG. Although the chances of developing glaucoma were comparatively higher in males but the frequency of blindness was more in females as compared to males. When the data was analyzed with respect to surgeries it was observed that more males were operated for PEXG and NTG. This shows more severity of these types in males while females had undergone more surgeries for POAG, PCAG, SIG and traumatic glaucoma as shown in table 2. Table 1: Overall prevalence and associated findings in different types of glaucoma Type (n) Mean Age (Years) Prevalence Blindness Positive family History Surgery POAG (1218) PCAG (571) PEXG (348) NTG (68) NVG (181) SIG (46) Traumatic (66) Glaucoma suspect (46) Others (265)

4 Akhtar et al. Effect of gender on prevalence of types of glaucoma Type POAG PCAG PEXG NTG NVG SIG Traumatic Glaucoma suspect Others Gender Table 2: Correlation of various types of glaucoma with gender Mean Age (Years) Prevalence (%age) Blindness (%age) 2 5 Positive family History (%age) Surgery

5 Al-Shifa Journal of Ophthalmology, Vol. 6, No.1, Jan/June, 2010 Discussion Nowadays gender differences in glaucoma is a topic of debate, therefore the present retrospective study was designed to analyze the prevalence of types, blindness and severity of disease with respect to gender. The results of our study are in accordance with most of the previous studies conducted in this regard. We have observed that females are more affected from Primary Closed Angle Glaucoma while males are more affected form Primary Open Angle Glaucoma. Certain anatomical factors might be responsible for such predisposition. It has been reported previously that eyes of females are on the average 1mm smaller than males as well as the lens and corneal curvature of females is steeper, therefore their applanation tonometry readings were more than half unit higher relative to males Recently Casson RJ et al had found in their study that female gender is associated with 9.2 times increased risk of closed angle glaucoma and each millimeter decrease in anterior chamber depth was associated with 2.6 times greater risk of this type of glaucoma. Similarly in a study of population of Nepal, the PCAG female patients were outnumbered than males 15,16. Most of the available studies and recent evidences have shown that females account for approximately 64.5% of the global blindness 17. According to a survey of the Chinese Ophthalmological Society cataract, the first leading cause of blindness is more common in females than male 18. Blindness due to trachoma was also observed two to four times at higher rate in females than males Recently in population of central Ethiopia gender differences were observed for blindness and low vision and they had found that women comprised 59.0% of blindness, and 7% of low vision. The difference in gender distribution and low vision was statistically significant in all age groups. Women had 1.46 increased risk of bilateral blindness 22. All of these studies are in agreement to our results which supports the notion that gender does have an effect in the prevalence of different types of leading eye blinding and neurodegenerative diseases. Although in all of these studies blindness prevalence is more in females than males but a study in Iran has reported that the blindness rate was higher in males as compared to females which is in contrast to our study. We were expecting our results similar to this because both of these populations are sharing a similar genetic history explained by a migration route of people from Iran to Pakistan. Similar results were observed in the population of Oman which also have migration routes from Oman to Pakistan and vice versa Contradictory to these results in the population of India, glaucoma is not gender specific 26. Gender differences in the prevalence of diseases might also be explained due to genetic factors or due to varying expression of different receptors and hormonal differences. It has been observed that sex hormones have an important role in the modulation of the structural characteristics and functional activity of many ocular tissues, including meibomian gland lipid release, corneal wetting time, conjunctival goblet cell density, and intraocular pressure due to which sex related differences in eye diseases such as dry-eye syndrome, glaucoma and age related macular degeneration has been observed Ogueta et al had found estrogen receptor protein only in the lens epithelial cells (LECs) of female whereas Rocha et al. have seen androgen receptor protein is existed in the LECs in male only 31,32. These findings highlight the importance of hormonal influences in certain eye diseases. Conclusion: Glaucoma like most of other ocular disease is gender specific and becoming and major cause of blindness. Large numbers of experimental studies are 5

6 Akhtar et al. Effect of gender on prevalence of types of glaucoma required to confirm these results as well the hormonal and genetic mechanisms which may lead to the development of these diseases in a gender specific manner to design the new therapeutic approaches and targets for the treatment and prevention of blindness. References 1. Tezel G, wax MB. Glaucoma. Chem Immunol Allergy. 2007; 92: Quigley HA, Broman AT. The number of people with glaucoma worldwide in 2010 and Br J Ophthalmol. 2006; 90: Ritch R. Natural compounds: evidence for a protective role in eye disease. Can J Ophthalmol 200; 42: Bickel H, Cooper B. Incidence and relative risk of dementia in an urban elderly population. Findings of a prospective field study. Psychol Med 1994; 24: Letenneur L, Gilleron V, Commenges D, Helmer C, Orgogozo JM, Dartigues JF. Are sex and educational level independent predictors of dementia and Alzheimer s disease? Incidence data from the PAQUID project. J Neurol Neurosurg Psychiatry 1999; 66: Musicco M. Gender differences in the occurrence of Alzheimer s disease. Funct neurol 2009; 24: Azad NA, Al Bugami M, Loy-English I. Gender differences in dementia risk factors. Gend Med. 2007; 4: Rudnicka AR, Isa SM, Owen CG, Cook DG, Ashby D. Variations in Primary Open- Angle Glaucoma Prevalence by Age, Gender, and Race: A Bayesian Meta-Analysis. Invest Ophthalmol Vis Sci. 2006; 47: Sheu SJ, Ger LP, Chen JF. sex as a risk factor for pseudophakic retinal detachment after cataract extraction in Taiwanese adults. Ophthalmology 2007; 114: Czepita D, Mojsa A, Ustianowska M, Czepita M, Lachowicz E. Role of gender in the occurrence of refractive errors. Ann Acad Med Stetin. 2007; 53: Goto T, Klyce SD, Zheng X, Maeda N, Kuroda T, Ide C. Gender- and agerelated differences in corneal topography. Cornea. 2001; 20: Mark HH, Robbins KP, Mark TL. Axial length in applanation tonometry. J cataract refract surg. 2002; 28: Mark HH. Corneal curvature in applanation tonometry. Am J Ophthalmol. 1973; 76: Mark HH. Corneal astigmatism in applanation tonometry. Eye. 2003; 17: Casson RJ, Baker M, Edussuriya K, senartne T, Selva D, sennanayake S. prevalence and determinants of angle closure in central Sri lanka: the Kandy eye study. Ophthalmology. 2009; 116: Rijal AP. Clinical analysis of glaucoma in hospital patients. Kathmandu University Med J. 2005; 3: Abou-Gareeb I, Lewallen S, Bassett K, Courtright p. Gender and blindness: a metaanalysis of population-based prevalence surveys. Ophthalmic epidemiol. 2001; 8: Zhang SY. Epidemiology of cataract in China. In: Jia-Qin Y, Lim A, eds, the frontier of Ophthalmology in the 21st century. Tianjin, Tianjin science and Technology Press, 2001; Melese M, Alemayehu W, Bayu S et al. Low vision and blindness in adults in Gurage Zone, central Ethiopia. Br J Ophthalmol. 2003; 87: Ezz al Arab G, Tawfik N, EI Gendy R, Anwar W, Courtright P. The burden of trachoma in the rural Nile delta of Egypt: a survey of Menofiya governorate. Br J Ophthalmolol. 2001; 185: Cromwell EA, Courtright P, King JD, Rotondo LA, Ngondi J, Emerson PM. 6

7 Al-Shifa Journal of Ophthalmology, Vol. 6, No.1, Jan/June, 2010 The excess burden of trachomatous trichiasis in women: a systematic review and metaanalysis. Trans R Soc Trop Med Hyg. 2009; 103: Woldeyes A, Adamu Y. Gender differences in adult blindness and low vision, Central Ethiopia. Ethiop Med J. 2008; 46: Fotouhi A, Hashemi H, Mohammad K, Jalali KH; Tehran Eye Study. The prevalence and causes of visual impairment in Tehran: the Tehran Eye Study. Br J Ophthalmol 2004; 88: Quintana-Murci L, Krausz C, Zerjal T et al. Y-chromosome lineages trace diffusion of people and languages in southwestern Asia. Am J Hum Genet. 2001; 68: Khandekar R, Mohmmed AJ. Gender inequality in vision loss and eye diseases: evidence from the Sultanate of Oman. Indian J of Ophthalmology. 2009; 57: Palimkar A, Khandekar R, Venkataraman V. Prevalence and distribution of glaucoma in central India (Glaucoma Survey- 2001). Indian J of Ophthalmology. 2008; 56: Mathers WD, Stovall D, Lane JA, et al. Menopause and tear function: the influence of prolactin and sex hormones on human tear production. Cornea. 1998; 17: Sator MO, Akramian J, Joura EA, et al. Reduction of intraocular pressure in a glaucoma patient undergoing hormone replacement therapy. Maturitas. 1998; 29: Esmaeli B, Harvey JT, Hewlett B. Immunohistochemical evidence for estrogen receptors in meibomian glands. Ophthalmology. 2000; 107: Smith W, Mitchell P, Wang JJ. Gender, oestrogen, hormone replacement and agerelated macular degeneration: results from the Blue Mountains Eye Study. Aust NZ J Ophthalmology 1997; 25(suppl 1): S13-S Ogueta SB, Schwartz SD, Yamashita CK, Farber DB. Estrogen receptor in the human eye: influence of gender and age on gene expression. Invest Ophthalmol Vis Sci. 1999; : Rocha EM, Wickham LA, da Silveira LA, et al. Identification of androgen receptor protein and 5α-reductase mrna in human ocular tissues. Br J Ophthalmol 2000; 84:

Glaucoma Related Morbidity at A Tertiary Care Eye Hospital

Glaucoma Related Morbidity at A Tertiary Care Eye Hospital AKHTAR F., ALI M. Al-Shifa Trust Eye Hospital, Rawalpindi Correspondence to: Dr. Farah Akhtar, Consultant Glaucoma House # 217, St. 49, F10/4,